T型管道不同封闭状态瓦斯爆燃火焰传播特征

为了研究分岔管道不同封闭状态下瓦斯爆燃火焰阵面传播规律，在自制的T型透明分岔管道内，设置支管端口完全封闭、直管左端口弱封闭，采用光电传感器和压力传感器测试了直管右端弱封闭、完全封闭2种情况下，预混甲烷-空气可燃气体爆燃火焰传播过程中速度、超压参数的变化情况。结果表明:由于分岔的存在，2种封闭状态在支管端点火后瓦斯爆燃火焰阵面在支管中的传播速度均先增大后减小；直管右端弱封闭时，经过分岔后火焰加速向直管两端传播速度基本一致，分别达到86.29 m/s和88.07 m/s；直管右端完全封闭时，火焰向弱封闭端传播速度增大至166.67 m/s，火焰向完全封闭端传播时并不断压缩未燃气体产生高压振荡反馈导致火焰振荡传播现象，火焰速度不断减小至4.84 m/s；管道内瓦斯爆燃超压均迅速上升到达峰值，之后受压缩气体的膨胀和冲击后爆燃产物的振荡作用迅速下降。

Propagation characteristics of gas deflagration flame in T type pipe with different closed states

In order to study the propagation laws of gas deflagration flame front in the bifurcation pipeline with different closed states,in the self made T type transparent bifurcation pipe,the end of branch pipe was set to be completely closed,and the left end of straight pipe was set to be weakly closed.The change of velocity and overpressure parameters during the flame propagation process of pre mixed methane air combustible gas deflagration under two conditions of weak closed and completely closed at the right end of straight pipe was tested by using the photoelectric sensors and pressure sensors.The results showed that due to the existence of bifurcation,both the propagation velocity of the gas deflagration flame front in the branch pipe under two closed states increased first and then decreased when igniting at the end of branch pipe.When the right end of the straight pipe was weakly closed,the propagation velocities of the flame accelerated to both ends of straight pipe after passing the bifurcation were basically the same,reaching 86.29 m/s and 88.07 m/s respectively.When the right end of the straight pipe was completely closed,the propagation velocity of the flame to the weak closed end increased to 166.67 m/s.When the flame propagated to the completely closed end and continuously compressed the unburned gas,the high pressure oscillation feedback generated and caused the phenomenon of flame oscillation propagation,and the flame velocity continually reduced to 4.84 m/s.The gas deflagration overpressure in the pipe increased rapidly to reach the peak value,and then the oscillation effect of the deflagration products rapidly decreased due to the expansion and impact of the compressed gas.